These electrical systems include electric vehicles having an electrical energy storage system which can be connected to power supply terminals by means of a recharging plug. The power supply terminals are each connected to the electrical grid.
Usually, charging the electric battery of such electrical systems begins the moment this battery is connected to the electrical grid and ends when this electric battery is disconnected from the electrical grid.
In the specific case of electric vehicles, the recharging begins the moment the recharging plug of the electric vehicle is plugged into the power supply terminal and continues as long as the electric vehicle is not unplugged, meaning until the user of the vehicle wishes to claim his vehicle or as long as the battery is not full.
This type of charging is not optimal, however, because the recharging does not consider constraints related to the grid, to the electric battery to be charged, or to the user of the electrical system to be recharged.
The constraints of the electrical grid to which the power supply terminal is connected can be expressed as the load curve of a transformer or of a delivery point, which is not uniform over time. For example, a transformer is stressed when its load exceeds its rated capacity.
The higher the load on the transformer, the more the transformer heats up, which accelerates its aging. In addition, large fluctuations in the load can result in sudden expansions and mechanical stresses. Ultimately, this transformer can grow louder due to the widening gaps.
As for the electric battery to be recharged, it can have widely varying charge levels when it is plugged into a power supply terminal, which determines the required amount of electrical energy to be obtained from the power supply terminal, and therefore the charging time required to reach a full charge.
Finally, concerning the constraints of the user of the electric recharging system, the user connects and disconnects the system at times which vary greatly depending on his schedule. When the electrical system is an electric car, the driver of the vehicle parks and reclaims his vehicle at times that depend on his schedule, which affects the available charging time of the power supply terminal.